SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e4a71b79e44ac741165504079f547021bc2629c749653886ea5da14e6b19460' 
  AND token = 'Pvn/YjNXk52zsYry2ajPLEEZ87lCESXW18BguvakIU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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