SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c88ccde029e8e28c994c66bbd7f0a591b35ecf7a44ab1369e2a1a98f44d3dc7' 
  AND token = 'AzFMZWA3TWYUn1VKhZzgNvVqYTwQt4NxoYcCC4pS3bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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