SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d9d1bcdc4adc5b951d825091b51e32314199adda67851a6e41480dd5d1c0801' 
  AND token = '6DpmwUtC6wmtWQ44i9WEjwxFqHd6J4vHkakPPsmLSbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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