SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efe4b190c5dd66ba705b0de6d79f6bb87191c168b854ac824fb8281bda04427b' 
  AND token = '3WJGyD0nfehUPn/Gq47P98gKeXo6u26EeefHJ48iBM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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