SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dd068e305444822341fb03cfb1992ecdbf5772f2ce08dbff730e99b458fd138' 
  AND token = 'LRGWM5Gkywq4rO3GqBFZhhD90ueHOcMwTvitTjyW0aA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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