SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad11bd9d93fbc9ea4a5d9fc450292f56befc30e2c48c4e665cf1ad12c972495b' 
  AND token = '+fm0yuIW0ls44FfUCsD4sgDhUjxXbooeVVZ4WmkDSkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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