SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '043b2e649dab89fa2ad904198f09d2f561e0701b1574d620193e150010f367c2' 
  AND token = 'OI/YwY25aFJ0vwibBPiLPxPIjl7PgAWFef/ZgKBnzhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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