SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb49bedb0957bf60060adeb803d35822e3eb34519149b182fc4b7130445cca97' 
  AND token = '1Oy/vAvrpDAA48YzKwhbXvOduahIBCVfGQEupPQn9CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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