SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90f49c544a2394d532689c158b120deb0be9aebd79dcbe07d0a569d7a5054eea' 
  AND token = 'NRO8jDviJtnjX7HBzdxMLQ/Iq292qrsrbYuCQ0vC30I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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