SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf7f1962025cbe5206920f8bd98059d11ba5601b6b5f483f8d67d030ef5bde9f' 
  AND token = 'DXy6C4REFzPkvu7Y1C/eHnDZ9sAdr/hrKSwsM+yRQqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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