SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abb17edd66c61a8e1296818fa9adf71c97bcb8ab564cf67447909fa5273cccb7' 
  AND token = 'KMGj+iH8qLpDm2dO3lx0QQcpEoKbjN2qC8osXrKANtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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