SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7cf924154dd931eb53579dd5290f06baa89a2624421adbded165e3bddbeef5e' 
  AND token = 'SgdYe+teXYT0Kk9F8Ji2kF+aeyBFYL2oOxiABCU4lmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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