SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2ecf4126bb1fa811bac5ad2553639d2b0e73d1c1935f5b3ab40a8f6c3fcc0dc' 
  AND token = 'lGAkYwlmQ2cLx5+yHlhTCmYnrS2qJRn+92Vns/7S3t8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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