SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ad3113423763ff8fa3e39335ba3725d88f4097c3c48519a9925a274fb9b30a7' 
  AND token = 'XoIsmPdT455soLPyFaCza7llt1uEtlPBfsZ1iobKNYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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