SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a2e2ec1f17c21d8b9a03dcf523606b4bba266f4293d4d65c605b45c4614afd6f' 
  AND token = 'm/E5KPmYuQs+TC0VPFY+qcNCwyEAIpLraU4aU8tzvcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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