SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '96b0d17116f9830c6f4e6262622d86bd16171893b3c0fae038a3d6d50158ccba' 
  AND token = 'ULUPsb749kFDt4ZTABDN1qwg5q/Dd3bpXBuYGo552Bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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