SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d3c98dca3daef2b867e9beb50d8f89eddafa85ea937691427de1fa53a23f432' 
  AND token = 'oEigyAYLLglFhKKnan7S48zfhmpBHCrrY792L8bysiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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