SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e993bfa1da4aaec6c67e7e429ecdbb2d60885cef1a660d38c1005eb6c6033a5' 
  AND token = 'OJpaVgn53/dH7gpNZ0rQnLae7aR2IuKMkfdkNawwzoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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