SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '555ec50c4adb061cc174fcbf3aa3162fdf7d5aab61cb7e593f9e6672344a4c30' 
  AND token = 'PmwfCZ6ja+QBTvxUNH1XFiEX50PfaKOZ9tAU818j5cA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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