SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54d724b6206eb928b2ea7e6fdbed04ccfd61e9d7bbe818ac11b52b384d3a36d0' 
  AND token = 'kSYHMwU7LkR3aNWa7rPnoj4OS5xvEMWHPGPSE7LhlxU=' 
  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"
    }
  }
}