SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93549da5a7f825663e0b18fee3c34d247c671d5833c5deba9218c4f9b1129c00' 
  AND token = '6rQNvlG38rlQ2mqwJjo6YrZSm0pHu9rrVEhNnsVxgKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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