SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca2dacb9531c9e1777782f0d6b99f6d6f474e87e9138228895bd3d3bbd7ba15a' 
  AND token = 'BFftlfMzlQrv5mllVuvzRRoDDjtApjpXX9BgFJBkrJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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