SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e19f605a951dd216c7ebfd33732936e906e42140883a6f0e7bfaf86854b80a7' 
  AND token = 'nNjUYLB7+Cx/lIpp+cYHJ3OZxA0GsJEaGpgR+mEyygY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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