SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b033f4e3cb20f8f4cfcd28e286cef9d580ca1da6db89a853d0970f7767708c8' 
  AND token = '5J1VDL3vvpo1icFfAVqoL0nCwSNftBAgfAHsAVZpM38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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