SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75caceb38b69096981f0c65a38bf27da5ed7c44200e2521997c4275480558c05' 
  AND token = 'Yip4B2Ws5ioqrxv9fRZVVrkuRmzPOgU5unA0ntRJJwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}