SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c79ffe8f20fdedd0c9fb496a288a5108bdf40de0f1ab0b182f0b199a8fd074b1' 
  AND token = 'VwPUE1iWuhjf8ENdr5K2x3co0ziWDpXrG3DWNB5WKGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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