SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a652eac9835c5b1ad8758fdfbcb2c311775e0fafa026992021ed9f3aab9e4e7d' 
  AND token = 'zNnweJDzZHJ/1Lbln+i8g0XkQhv+9L/xgyzjp5PfGpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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