SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b1522034fb559ddd4b808810dcbc0caee36129f57c1697cf1a028fab9acd6d4' 
  AND token = 'y+dOOEJfzmm94MjV1Ja1LpjhuJ9FoRdIvYFSB4INVUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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