SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31d2730916bfeadf0ac9f697821ce73fbdae0e70da3406b94816ae020a04d2a3' 
  AND token = 'JeG9ZI3uACLsMrbe97zqwKVuQwNoxE8lcvGexTl4TY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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