SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29854f2c6bdd3ba8ccfe2998b3dbd4b558c44290f57864fe263361dd0e8e08c0' 
  AND token = 'c0jKtbESAfGppwnnl/duYDj+ygPq6drrex4S5O0stto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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