SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4829ffb6497537f097d6f60f81b41faa5323c25bfb9ddc67bb74dccd8acea351' 
  AND token = 'HvAfavi6n/9+BlTBL0raWQcKDU0ZNOTcuBvNwQvMU0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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