SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c5eb9e3ccefc014262a9afdafe01243e012b82c4c0dcfa69bf3c430fa8093e7' 
  AND token = 'dJ+zbLA5CLEB/ku0BrSBjRVzEOOXyrT1oAjKuweyx7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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