Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b54b7f949afe4793798fd5be88e4f70c9944dbc68b26bdcf3ccddf1e00fd5d21' 
  AND token = 'k8bw9aj2wkPNUkYUWZsnBbbji9qFtZx4sNHO8fjEcVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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