SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9a4eddea8964ff4bb360ac76efd1c0b4cfb805ec48686c333da425f061d1b86' 
  AND token = 'y9EnSf45mUCqEWboRLh03Q59HloONQVQrr0vhaPnHgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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