Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9af2a2d584174c89a5940b2a1137ceef21877c4ece96ea351d00acb8cecbcd3' 
  AND token = 'sK48ZCvakiWN3HbSDQnBIfNIlPUNxxRpYRh7w1t+GCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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