SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61bfcaa286138a1e1ddcc6cba87951671e362d3f0bb314ad4e6ec210d324c9f3' 
  AND token = 'USz1AJ94xkJV5EajKMeHlbE6mvM04AOW2AERxPrOcJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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