SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d6e8c410ba725745ad1d12259fdfe94f33442ea7936ec85b8207d55a94a1e3e' 
  AND token = 'zAJXJiMHrIoIxnHwBWakR9Fx+Qi0/tTWzZVX/Vg/1pQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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