SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '454e5dbd6e7462fc9ccad17350ded380d6e94874309e448378b37d49ed482ba9' 
  AND token = 'OJVA/YL6zVpW/mvy+UYOBCG8s8bICTydFYvqTSK5CE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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