SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc7461e9d648878983036fe276b995adf035414c094d5116820b41f4203aedf' 
  AND token = 'dVpexMTC45EdyyTXHURVI9umEJKN6G4c6qMCmvEdEiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}