SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f580d95b1de07be266daece0896a693b5e8000f67a2489bf4df6192f5bcd14b' 
  AND token = 'QySgwC+9BdD7RA85iFM+jlVYR7GUmAnE+e44rzMb0sE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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