SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cf2b0403b6bf9d30b42b2e447e3f2f762aaf7985039012a4d3955982724b128c' 
  AND token = 'kUmbl2Oi/Kg0WJH1/SsLjcux1xmagHuOgWIcvXyBBfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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