SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b57765ef421af3089395c6e3481b617edead30e2fd278d87c4317de98aba362' 
  AND token = '4/9EE8Q0mVbpUEQn6+pQpPkzqu6qudXPnIWUeLqatFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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