SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c63032000e22f6de1f9685ff51dfad2f4d3d5ff7d5907e262fb5d16853db5ba4' 
  AND token = 'vubGMwHvHj+NAW4+gNBW+mKPt0LzgTzQvGpyizeVLqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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