SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a85fe3a2e8b96624125fbeceeaf46ceaa39b6c5de584a309c4efe92a430c4ff6' 
  AND token = 'aD4nLqSrbWTZevZGIEJA5S+DcohikezVPgd+rm4ikpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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