SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c6894bb589202ba85eb159fb7b9fdb8c1a2db170123ba992b0f1b3c39da5877' 
  AND token = 'fpWwutVXwJ2fqA0KTYtFzfEqUyf8lXsTKjhuFtfitnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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