SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d837879b0d360e3df0e10baf0fbc6bab82bc885d3289033c100a8225525307d' 
  AND token = 'ewEMoI9Ta0I1zvdyyFYs6oJZLuUxUBTceF8zUTPEyqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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