SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8714458030bde7df499178ccf08a72bdcda45fe3ec18b5bb31eb643d5cbb1aa6' 
  AND token = 'wnINeOJjoZGSUIyl6+nM21LsNQVgAdsLsplRgs2aSyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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