SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd5e6b1794bbbfd791af8f9547593c33e99dfc33ea485091315c37e4810dd3a3' 
  AND token = 'wmIN2135v3fjeVPthlBgjGw5+tdjrC6pF1ChF+rOX+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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