SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a14336ff2913905f4640d06419fa27b0c3c0dd27f81a3ce40668827be3500bda' 
  AND token = '8qjpjzWdAZ9lhuBAD9zrf+pwy4QaSSVXSjaVTe5BZxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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