SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20628a8cca2f909747ac2cbd0b5f34987c96edefa6ee16e886915a7781c47cee' 
  AND token = 'NCFyDiT+mxp+uoixd/qywblDp81GdoW2vvpVr1FnKiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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