SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a148f3e1842b535b96a1e5703d009ad5a9cb4225a85a8c7c5404ebdf99881e' 
  AND token = '4WLn5NtL9ILLmpyNlJewJerlo9zaTq4P6Q5jrbAICV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}