SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5671c15edfa31fcba6325837649783d774e5c92d5257fe9b7379679873800fdb' 
  AND token = '2A0K+Xn5OvuMNGHYTjqwhr+mUEXyZ8EiU/Huqqlj4MM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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