SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd190542012511d2ff3d851cfd52edc9d5847548697a59eafeffea721d1db64ac' 
  AND token = 'bi3DfURBZlraCTi4198QF7eh2Dyc4kS/gPrYub7tSLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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