SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9314d9992dea2eb4b6243be356f73cf22345eceb6a8a498f3bcbb8a5505a6a9' 
  AND token = 'Q/eANKretdMGCfP9gGDTtw0RPuwCsid2zoSuszZ03oE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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