SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e9c31eeeb18d9a27ad95c48ed556735109ce78cb295581fab7b9cfc9c07a6da' 
  AND token = 'KF2vqq0RL9zoUOSF0JwzRBq6s0iEecbAUgCocwkPJpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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