SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f61dc568ab96b4ce653a99da5ae50e4c15563dcbd76b404913ff7c6eeb51b71d' 
  AND token = 'FXfqOmwYhUCSWQlayMjDR1ak/NxMbrcm5tFWqfjLkTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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