SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d72f08b877e5f98e39f2d83bf43c652c0b72b4b30814064b118d87a9d41d65b' 
  AND token = 'ALUjHFGASnKpWCb94HhAynTXB2ZX8MN0TmaZanQfqfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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