SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ddef08f34e81873dfbb2258684686dcc9a2ce3af4a00769c1c39da8de1edf6b' 
  AND token = 'OT7zHIQ80bkFQYo5keBn4ExMvZEYppLPLebnziBeG7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00103

JSON explain

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