SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '083eda6b522e78f15dd70adf959c670db122fac1d74eb66da90b027c241f990a' 
  AND token = 'X6UhZmzXiVqqkn2bmVDE5fLCp/th3B00pho/RqeRHmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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