SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ebb363ffdba99ebe30996ba271b56c83a81a4e92f820c433f0126d78c9c01d3' 
  AND token = 'ZxBuqnwHj0RcGMvHefdHknpBng4InJfFFnljt90N2YI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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