SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb3f64783fc12635774330bf3f308199a85bdeedebfef7399e167b1f626c236' 
  AND token = 'WaLtj02GhJNhNXAmm7WTrVsT3aUDHhvYYROkV3kAZvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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