SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ac4fb75651ff547ca5958cf10e1384c9f1d997ead94cec6f955c0a1f57c78bc' 
  AND token = 'AT445TlXA58GJldddetz4Zq+UIhIOWTZcpoYZ2B2Mmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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