SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3901eb0aec9b655cbc0e734b7063ce193bdbf18eb4aa07053d945130a8173a4c' 
  AND token = 'GLLmTrC2/CnfpDiAGUi/Tp4uQs4qvCwfqn0znJ7ZNPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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