SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f99ee00368f040a6a1bc1f0e875d27d7059870273b96c7a08cac08952dbac30' 
  AND token = '9Gc5ADkz1zx8CZYnUG1jB8CP58kWtnXfM7lMIl7q26U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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