SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9757ed9b730ceae2b9e088d69413fde0852d56a2e319853018784256dc982c1' 
  AND token = 'tBS9sjz+sCHBCbiMkVW1lKaowfdaGpO/GleMEwLKvnY=' 
  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"
    }
  }
}