SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fed8c16108a816055ede368aeeeff742a46804c3aa6e2b5d505ea2a68e7c2a2e' 
  AND token = 'OvD8rvXS9vc8LGMXfJjToOemkqCdIcNwIlLsK565dgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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