SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06734675626986a735610b833dc4ef488e29e7c8887b05ca7673c4ee12482758' 
  AND token = 'lPmTV22L9DktoVxuaN2Sc9pO1h1qhxzCTdRYShikxzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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