SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca295e19e77de76d0f9b35a0b755108e01add5bd88beafdcf8d48259bf9bb1a3' 
  AND token = 'TfQ3hhfy7Aam2+5Ny62y0onHK81XSOl0dUWOwK8YEdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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