SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1751a7bcfe9c313241d15f622ae916ca54f63bebd20d8bf9158bd766833283c2' 
  AND token = 'hPyzBTqPiaRbFRasT46DMy2mQmHPQU8lK6F82RFqAPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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