SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87d5f9e090c6788a910a6b6cce1fd2e574f1a3e3cc46d18b1907326521642cf4' 
  AND token = 'icKYamNP6JOz+LBabnUC9HZfi40b8gzdwwdfB2H4/uQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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