SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '360a94e58e9dfb8349c3efa5024a956ce9baaba39f1e177faaf6ace58114e88f' 
  AND token = 'BikPXNKIrIiywnpJ9W4+QI8JEsv7zFQGQ/UdwGsXOtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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