SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd03745ac25cf2e8e27162d3d2aee02da184602337726eef6341beae248f6dd83' 
  AND token = 'WaCv+EvFPYJwAWbgRhenl+KnkFZBYrfeed/MyZhbQ6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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