SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d676d269d5c2a359873225502eb3f0a5e0cc9fbb036dfa792b53d41460d04bf' 
  AND token = 'QXZ31LtWQ6/7Xs2CShWfVBkeGktCeXjumzomrjZ86d4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}